Hoist apparatus

ABSTRACT

INVENTION RELATES TO A LIFT HOIST INCLUDING AUTOMATICALLY CLOSING CLAWS WHEN THE LOAD IS CONTACTED, THE CLAWS ARE PIVOTED ON A BASE PLATE CONNECTED TO A SUSPENSION DEVICE AND CO-OPERATING WITH A DIFFERENTIAL DEVICE, SAID DIFFERENTIAL DEVICE BEING ATTACHED TO THE CLAWS AND OPERATIVELY ASSOCIATED TO A DISPLACEABLE PISTON CONTACTING THE LOAD.

www@ Sies @www [191 Butz [451 Fel). 27, 1973 [54] HOIST APPARATUS [76] Inventor: Erich Dagobert Butz, Kahlweg 46,

605 Offenbach am Main, Germany [22] Filed: May 26, 1970 [2l] Appl. No.: 40,572

[52] U.S. Cl. ..294/112, 294/106, 294/1 l5 [5l] Int. Cl B66c 1/64 [58] Field 0f Search...294/l06, ll0, lll, ll3, 115,

2ll/ll7, ll2

[56] References Cited UNITED STATES PATENTS 3,099,476 7/1963 Miller 294/1 13 ll/l960 Cianchette .294/106' 4/1965 ll/l967 Kilner .294/ l 06 Meissner ..294/1 l5 Primary Examiner-Even C. Blunk Assistant Examiner-Johnny D. Cherry Attorney-Holman & Stern [57] ABSTRACT invention relates to a lift hoist including automatically closing claws when the load is contacted, the claws are pivoted on a base plate connected to a suspension device and co-operating with a differential device, said differential device being attached to the claws and operatively associated to a displaceable piston contacting the load.

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Attorneys HOIST APPARATUS BACKGROUND OF THE INVENTION The invention relates to a lifting hoist withautomatic closing parts for lifting a load.

Known types of lifting hoists suffer from the disadvantage that the hoist parts open if the load tilts, or the load may shift laterally in relation to the hoist parts and may eventually slide out of them.

SUMMARY OF THE INVENTION The present invention suggests improvements in hoist parts to prevent shifting of the load and to ensure that the hoist operates safely, even if the load tilts.

Accordingly, the invention provides for the hoist parts pivoted on a base plate to be connected to a suspension device, on the one hand, and co-operate with a differential device, on the other, one part of the differential device being connected to the hoist parts, while its other part is connected to a displaceable piston engaging with the load.

This piston provided according to the invention applies a pressure to the load, in the direction of the gravitational force. The connection between the piston and the hoist parts ensures that the former will open only if a force acts on the load in the direction opposing the action of gravity. This is the case, for instance, when the load has been placed on the ground and the weight of the hoist acts on the load, through the displaceable piston. l

The hoist parts can now be opened by the reaction of the piston through the differential gear on the hoist parts.

To compensate for different widths of the load, for instance, to enable the hoist to be adapted to the different flanges of rolled joists, the differential device can be designed according to the invention as a compensation differential.

Different arrangements can be provided for the practical design of a hoist according to the invention.

One of the possible alternatives may be formed by a combination of toothed racks with interposed pinion, according to a further feature of the invention.

With suitable positioning of the pinion, this arrangement can operate as a compensating differential.

According to a further feature of the invention, a compensating differential can also be arranged in the form of a device with loose pulleys, where the pulleys operate with one rope capable of being used at the same time for suspending the hoist.

The invention covers also arrangements of hoists cooperating with a locking gear enabling the grab to lock automatically into its open position so as to prevent self-closing of the grab parts.

The loose pulley arrangement can be designed in different ways. In one of these arrangements, one loose pulley is allocated to each of the grab parts, while a third loose pulley is supported on the piston.

According to another arrangement of the invention, the pulleys accommodated on the grab parts are supported on a common shaft retained in slot guides of the grab parts.

The aforementioned third loose pulley engaging with the piston can also be arranged in the form of a nonrotatable rope guide as in the practical arrangement of the invention it is purely intended to provide for more compensation of the rope ends leading to a suspension device.

With the adaptation of thc grab to different flange widths of the rolled section loads, different angles of opening of the grab parts are obtained when the grab carries a load. It is accordingly convenient to make the grab claws in such a way that they can safely grip the load at all practical angles of aperture.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be explained by way of example with reference to the drawings, wherein:

FIG l is a side view of a first embodiment of the invention;

FIG 2 is a plan view of the arrangement illustrated in FIG 1;

FIG 3 is a cross-section along the trace III-III of FIG 2;

FIG 4 is a longitudinal section along the trace IV-IV of FIG 2;

FIG 5 is a longitudinal section along the trace V-V of FIG 2;

FIGS 6 to 8 are diagrammatic side views of the arrangement according to FIG l, with different flange widths of a load of rolled sections;

FIG 9 is a longitudinal section through a second embodiment of the invention',

FIG l0 is a cross-section through the arrangement of FIG 9;

FIG 11 is a longitudinal section through a third embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION FIGS 1 to 8 may serve to explain a general example of an embodiment. FIGS 9 and 10 show a modified embodiment of a hoist suitable also for very narrow sections, and extending the range of application.

FIG 11, to be described first in the following notes illustrates a third embodiment and also the basic principle of the invention.

According to FIG 11, the mechanism of the invention is arranged between a pair of base plates 10 forming together a casing.

Hoist parts I2 are hinged on pins ll fixed to the casing. These parts are equipped at their lower ends with claws 13 for engaging the load.

The parts l2 have pins 14 as hinges for links l5. Each of these links l5 is pivoted by means of a pin 16 on a toothed rack 17. This rack is guided in guide parts 18 so that it is vertically displaceable in relation to the casmg.

Suspension parts 19 such as ropes or chains engage at the free ends of the rack 17 The racks 17 mesh with pinions 20 rotatably supported on pins 2l fixed to the casing.

These pinions 20 engage also with second racks 22 guided in guide parts 23 so that they can move vertically in relation to the casing.

The lower ends of the racks 22 form pistons 24 normally projecting from the bottom part of the casing.

The racks 22 are loaded by tension springs 25. The racks 17 and 22 form together with the pinions 20 differential devices of known operating mode. Shifting one of the racks by a certain distance in one direction brings about shifting of the other rack by the same distance in the opposite direction.

The device described above operates in principle as follows:

The hoist is dropped onto a load, in the embodiment shown here a fairly large tank 30.

The pistons 24 meet the surface of the load and move upward in the direction of the arrow 26. This causes the rack 17 to move downward in the direction of the arrow 27. The motion of the rack 17 causes the parts 12 to open as long as the hoist is lowered further by a suspension device, for instance by a crane.

The parts are opened so far that they can engage with the flange 31 of the load 30.

Lifting of the hoist from the suspension parts 19 has the result that the racks 17 move upwardly so that the hoist parts are swivelled into the position shown in the drawing and grip the load under the flange 31.

The shifting of the racks 17 during the lifting of the grab not only causes the parts 12 to close but also the rack 22 to move downwardly in the direction opposite that of the arrow 26.

The pistons 24 now push firmly against the load and with the aid of the differential (22, 20, 17) prevents unintended opening of the grab parts 12.

It is clear that the arrangement described above operates satisfactorily if all loads to be lifted are of exactly the same sizes.

If the arrangement is to be adapted to different load widths, the differential device has to be arranged in the form of a compensating differential.

This can be done in the embodiment described above by making the pins 21 of the pinions 20 displaceable in a vertical direction in the base plates 10.

The embodiment illustrated in FIG 1l represents a hoist according to the invention, suitable for extremely wide loads.

It can be arranged to suit narrower loads by making the racks 22 as a single rack.

The embodiment of FIGS 1 to 5 shows a hoist 100 for the lifting of tees or joists with upper flanges of different widths and/or thickness.

FIG l shows a side view illustrating all parts of the arrangement for two different positions of the hoist parts.

The plan view of FIG 2 is mainly intended to show the position of the traces for the FIGS 3 to 5 and the locking device, this device being explained in more detail below.

The hoist denoted by the number 100 has two lateral base plates 101, a cover plate 102, and side plates 103. These plates form together a casing accommodating the movable parts of the hoist. The cover plate 102 has holes 104 for suspension ropes 105.

To the base plates 101 two shafts 106 and 106a are fixed as pivots for the grab parts 107 and 107a. These parts are substantially bent levers and have at the lower ends claws 108 and 10811 for engaging with the load to be lifted, such as a T section 109.

The inwardly projecting legs of the grab parts 107 have shafts 110 and 110a for the rotatable support of rope pulleys 111 and l 11a.

A piston 115 is arranged inside the grab casing 100 by means of guides 112 (FIG 4) and 113 and 114 (FIG 3) so that it is displaceable in the vertical direction.

The piston 115 has an elongated hole 116 in its middle part.

The upper part of this piston is also guided in an aperture 117 of the cover plate 102.

The piston has near its upper part a shaft 118 rotatably supporting a rope pulley 119.

The suspension ropes 105 are guided roughly in the shape of a letter U about these rope pulleys 111, 119, and 111a, as shown in FIG 4. FIG 5 shows that the downward pointing arms of the grabs are equipped with pins and 120a.

Guides 121 and 121a are hinged to these pins on both sides of the grab parts. These guides are joined together by a common shaft 122, passing through the elongated hole or slot 116 of the piston 1 l5 and guided in it so that it can slide in the vertical direction. Drivers 123 and 123a are supported on the shaft 122 near the two ends but outside the base plates 101.

These drivers are fixed to the upwardly extending guide rods 124 and 124a.

The guide rods are guided in bores of the cover plate 102. Compression springs 125 and l25a are accommodated on the guide rods and resting on one side against the cover plate, and on the other side against the drivers 123 and 123a, respectively.

The guide rods 124 and l24a are arranged together with the springs supported on them and the drivers in outer casing parts 126 and 126a, respectively, so as to protect them against dirt. The shaft 122 is guided in vertical elongated holes or slots 127 in the base plates 101.

Upwardly projecting lugs 128 and 12811 are arranged on the upper side of the cover plate 102, a lever 130 being hinged to the lugs by means of pin 129.

Angular locking parts 131 and 131a, respectively, are fixed to the lever, with their lower legs projecting outward into the path of the guide rods 124 and 124a, respectively.

The operation of the hoist according to FIGS 1 to 5 follows from FIG 1.

As long as the hoist is not loaded, its weight is suspended from the rope pulleys 111, 111a, 118. This causes the hoist parts to assume a closed terminal position because their horizontal arms are moved upward by the rope pulleys 111 and 111a being pulled to the top. The pulley 119 is moved together with the piston 115 downward. The piston accordingly projects a specific amount below the lower side of the casing 100.

If now the hoist is placed on the load to be lifted, the piston 115 is lifted in relation to the casing 100. At the same time, the weight is reduced, so that the parts open automatically.

This position is shown in chain-dotted lines in FIG 1.

In this position, the guides 121 and 121a, the drivers, and thus also the guide rods 124 and 124:1 are in their lower positions, the upperends of the guide rods 124 and 124a move back until they are close to the cover plate 102, so that the locking parts 131 and 131a can move over the ends of these rods.

The lever 130 now drops into the position shown chain-dotted in FIG 1. The hoist parts are now locked to prevent their closing, even if the hoist should now be lifted. In this case, the entire weight of the hoist is carried by the locking parts 131 pushing against the ends of the guide rods 124.

If a load, such as a section 109 is to be lifted, the lever 130 must be placed by an operator in the position shown in full lines in FIG 1.

The guide rods 124 can now be pushed downward. When the hoist is lifted, its own weight now rests on the pulleys mentioned above. These pulleys are made by the arrangement of the ropes to close the hoist parts and move the piston downwards. At the same time the guide rods are moved upwards by the guides.

The guides continue with their swivelling motion until they come to rest against the side edges of the upper flange of the rolled section 109, as shown in full lines in FIG 1.

The weight of the lifting rod causes also the pulley 1 19 to move downward and it takes the piston 11S with it. The piston 115 now comes to rest on the top of the upper flange of the rolled section 109.

lt can be seen that the grab parts will close more firmly, and the force exerted by the piston 115 against the top surface of the load is the greater, the heavier the load.

The side edges of the upper flange of the joist 109 are pushed in this manner firmly against the hoist claws 108 and 108a. Since this thrust is also equal to the weight of the load, the force acting on the hoist claws is twice the weight of the load. This secures the load against slipping or tilting in the hoist.

FIGS 6 to 8 show diagrammatically the arrangement of FIG 1 in the positions assumed by it when carrying loads 109a, 109b, 109e, of different sizes.

A comparison of the various angles of spread assumed by the hoist pa'rts under these conditions shows that the design of the claws is a very important matter.

These claws must be designed so that they can safely grip under the top flange of the load section at the various angles of spread. When the load is dropped, the pull in the suspension ropes 105 is relieved. This causes the claws to open automatically and the piston to move upward into the position shown chain-dotted in FIG l. Since the guide rods 124 and 124a are also automatically moved downward, the lever 130 drops automatically nto its locking position, with the locking parts 131 and 131a.

The parts remain open even if the hoist is lifted again.

It can be seen that the field of application of the embodiment shown in FIG 1 is confined to sections with an upper flange not narrower than the distance between the shafts 110 and 11011. Narrower sections cannot be safely gripped.

The example shown in FIG 6 represents almost a lower limit. In order to enable the hoist to lift also narrower sections, the shafts 110 and 110a can be arranged in line. But since this would involve considerable design difficulties, the invention suggests a different solution, shown by way of example in FIGS 9 and 10.

Two parts 152 and 152a are pivoted on through shafts 151 and 151a in a casing 150.

As shown in the embodiments described above, these parts are in the shape of bent levers. A piston 153 is vertically dsplaceable by means of guides not shown here in detail in the inside of casing 150. This piston has in its middle part a slot or elongated hole 154.

The inwardly projecting arms of the hoist parts 152 and 152a have elongated holes or slots 155 and 155a.

One shaft 156 passes through each of these slots of the piston and of the hoist parts. This shaft carries a slider at the places where it passes through the aforementioned slots, the sliders being guided each in one of these slots.

In order to ensure uniform loading, the inwardly projecting arms of the hoist are made forked as shown in FIG 10.

Rope pulleys 157 and 157a are rotatably supported near the ends of the shaft 156.

Rope guides 158 and 158a preventing dropping out of the rope 160 are arranged above the rope grooves of the pulleys 157 and 157a. The upper end 159 of the piston 153 is saddle shaped and has a diagonal rope groove. A clamp 161 accommodated on this saddle prevents the rope slipping out of this groove.

The rope 160 passes over these pulleys as follows, starting from the top: The rope 160, coming in FIG 9 from the top, is guided in the downward direction over the pulley 157. It leaves this pulley in the upper direction and passes diagonally, as shown at 160', over the saddle of the piston and then passes over the rope pulley 157a, leaving it here as shown at 160", and leaving the casing in the upward direction.

A lug 162 is provided on at least one of the hoist parts 152. One end of the tension spring 163 engages with the lug. The other end of the tension spring is connected to the casing.

This tension spring 163 applies a prestressing to the hoists in the direction of the opening position.

This opening position is limited to the outside by the edges 164 of the holes in the casing. A lug 165 on the hoist part 152a has a rod 166 hinged to it.

This rod has a telescoping extension 167 with an external handle 160 and it is guided in an aperture of the casing. The extension of the rod 166 can be adjusted by means of parts 169. According to the position of one of these parts 169, the opening of the parts is limited and a locking action is obtained, similar to the one of the previously described embodiment.

The locking element is a slide mounted on the casing and engaging behind the projections 169 as they leave the casing.

It can be seen that this arrangement operates in the same way as the embodiment of FIGS 9 and 10, and also as that of FIGS 1 to 8.

The saddle surface 159 of the piston 153 replaces the pulley 1 19 of the embodiment according to FIG l. This pulley has in any case only the function of compensating for different extensions of the two rope ends leaving the casing in the outward direction.

A rotatable pulley is not absolutely necessary for this compensation. It is adequate to guide the rope over a curved rope groove adequately lubricated to overcome the frictional resistance.

I claim:

1. A hoist-clamp for automatically gripping and stabilizing a load being lifted in relation to the gravityforce imposed on the hoist-clamp by the load, comprising in combination:

housing means;

opposed jaw means pivotally mounted on said housing for engaging opposite sides of the load;

piston means displaceably mounted on said housing for moving away from and into engagement with said load in relation to movement of said jaw means with respect to the load;

means operatively connected between said jaw means and piston means for coordinating respective movement of the same; and

suspension means operatively connected to said means, operatively connecting the jaw and piston means for lifting the hoist clamp whereby both the piston means and jaw means are urged toward said load in relation to gravity-force of said load;

said coupling means comprising anti-friction means on said jaw means and said piston means, said suspension means comprising a cable reversely entrained over the anti-friction means of said piston means and beneath the anti-friction means of said jaw means and providing differential movement therebetween.

2. The combination as set forth in claim l including spring means operatively connected to said means coordinating respective movement for normally urging said jaw means apart.

3. The combination as set forth in claim 2 including locking means on said housing operatively connected to said jaw means for retaining the jaw means in an open position in opposition to said spring means.

4. The combination as claimed in claim l in which said means coordinating respective movement of the jaw and piston means comprises coupling means for said jaw means vertically displaceable relative to said housing whereby said jaw means can accomodate loads of different widths.

5. The combination as set forth in claim l in which said anti-friction means on said jaw means comprises pulley elements journaled thereon.

6. The combination as set forth in claim 1 in which said anti-friction means comprises a pulley element journaled on an upper portion of said piston means.

7. The combination as set forth in claim 6 in which said jaw means comprise lever elements intermediately journaled on said housing on mutually parallel axes of rotation, said lever elements including lower load-engaging portions extending toward each other, said lever elements including inwardly directed upper portions upon which said pulley elements are journaled, said piston means being disposed between said jaw means and having a lower distal load-engaging portion.

8. The combination as set forth in claim 7 in which said piston means has a lost-motion slot extending in the direction of movement of said piston means, said upper inwardly directed portions of said lever elements being pivotally connected to a shaft reciprocable in said lost-motion slot.

9. The combination as set forth in claim 8 including supplemental lever elements pivotally connected to said jaw means and said shaft, and spring means interposed between said housing and said supplemental lever elements for normally urging said shaft downwardly and said jaw means apart.

10. The combination as set forth in claim 9 in which said spring means includes guide rods connected to opposite ends of said shaft and reciprocably guided on said housing, and compression spring elements on said guide rods.

11. The combination as set forth in claim 10 including locking means comprising a lever member pivotally mounted on said housing, said lever member including a portion movable in a path intersecting the path of movement of at least one of said rods for engaging and retaining the same in a fixed position.

* #Il =I 

1. A hoist-clamp for automatically gripping and stabilizing a load being lifted in relation to the gravity-force imposed on the hoist-clamp by the load, comprising in combination: housing means; opposed jaw means pivotally mounted on said housing for engaging opposite sides of the load; piston means displaceably mounted on said housing for moving away from and into engagement with said load in relation to movement of said jaw means with respect to the load; means operatively connected between said jaw means and piston means for coordinating respective movement of the same; and suspension means operatively connected to said means, operatively connecting the jaw and piston means for lifting the hoist clamp whereby both the piston means and jaw means are urged toward said load in relation to gravity-force of said load; said coupling means comprising anti-friction means on said jaw means and said piston means, said suspension means comprising a cable reversely entrained over the anti-friction means of said piston means and beneath the anti-friction means of said jaw means and providing differential movement therebetween.
 2. The combination as set forth in claim 1 including spring means operatively connected to said means coordinating respective movement for normally urging said jaw means apart.
 3. The combination as set forth in claim 2 including locking means on said housing operatively connected to said jaw means for retaining the jaw means in an open position in opposition to said spring means.
 4. The combination as claimed in claim 1 in which said means coordinating respective movement of the jaw and piston means comprises coupling means for said jaw means vertically displaceable relative to said housing whereby said jaw means can accomodate loads of different widths.
 5. The combination as set forth in claim 1 in which said anti-friction means on said jaw means comprises pulley elements journaled thereon.
 6. The combination as set forth in claim 1 in which said anti-friction means comprises a pulley element journaled on an upper portion of said piston means.
 7. The combination as set forth in claim 6 in which said jaw means comprise lever elements intermediately journaled on said housing on mutually parallel axes of rotation, said lever elements including lower load-engaging portions extending toward each other, said lever elements including inwardly directed upper portions upon which said pulley elements are journaled, said piston means being disposed between said jaw means and having a lower distal load-engaging portion.
 8. The combination as set forth in claim 7 in which said piston means has a lost-motion slot extending in the direction of movement of said piston means, said upper inwardly directed portions of said lever elements being pivotally connected to a shaft reciprocable in said lost-motion slot.
 9. The combination as set forth in claim 8 including supplemental lever elements pivotally connected to said jaw means and said shaft, and spring means interposed between said housing and said supplemental lever elements for normally urging said shaft downwardly and said jaw means apart.
 10. The combination as set forth in claim 9 in which said spring means includes guide rods connected to opposite ends of said shaft and reciprocably guided on said housing, and compression spring elements on said guide rods.
 11. The combination as set forth in claim 10 including locking means comprising a lever member pivotally mounted on said housing, said lever member including a portion movable in a path intersecting the path of movement of at least one of said rods for engaging and retaining the same in a fixed position. 